The question itself is controversial, as we're not sure if the observer has anything to do with the wave collapse.

However, once the ability to observe (or interact) with a given particle is enabled, the wave-function or probability wave of that particle peaks, or collapses into a finite quantity.

As said, we're not sure if a conscious observer has anything to do with it, or if it has to do with physical interactions in and of themselves.

Another opinion:

The observer has nothing to do with the collapse of the wave function. It is the measurement acting on the the wave function that does the collapsing. The part about which we are uncertain (we, as in physicists) is whether nature performs the measurement before we do and we get the result, or if nature leaves the wave function as a superposition until we measure it. This is the fundamental question of Schrodinger's cat in a box paradox.

The official definition for the word wave function is "a function that satisfies a wave equation and describes the properties of a wave."

Square the wave function.

The differential of the sine function is the cosine function while the differential of the cosine function is the negative of the sine function.

to open mouth when patient is collapse